Table 7Calculated hazard ratios for aspirin versus placebo or no antiplatelet

Study PopulationType of Study
N Analyzeda
Comparison
Quality
Length of FollowupResults Reported by AuthorsCalculated HR (95% CI)b
Belch, 200854

POPADAD Study

Patients with diabetes mellitus and asymptomatic PAD
RCT
N: 636
ASA vs. placebo
Good
6.7 yrNonfatal MI:
ASA 34, no ASA 28

Nonfatal stroke:
ASA 11, no ASA 22

CV mortality:
ASA 20, no ASA 11

Composite vascular events:
ASA 58, no ASA 57
Nonfatal MI:
0.98 (0.68 to 1.42)

Nonfatal stroke:
0.71 (0.44 to 1.14)

CV mortality:
1.23 (0.79 to 1.92)

Composite vascular events:
0.98 (0.76 to 1.26)
Catalano, 200755

CLIPS Study

Patients with IC
RCT
N: 181
ASA vs. placebo
Fair
2 yrNonfatal MI:
ASA 0, placebo 2

Nonfatal stroke:
ASA 0, placebo 5

CV mortality:
ASA 2, placebo 3

Composite vascular events:
ASA 1, placebo 10
Nonfatal MI:
0.18 (0.04 to 0.82)

Nonfatal stroke:
0.54 (0.16 to 1.84)

CV mortality:
1.21 (0.32 to 4.55)

Composite vascular events:
0.35 (0.15 to 0.82)
Fowkes, 201056

Patients with asymptomatic PAD and no previous cardiovascular disease
RCT
N: 3350
ASA vs. placebo
Good
10 yrNonfatal MI:
ASA 3.7%, placebo 4.1%

Nonfatal stroke:
ASA 0.4%, placebo 0.7%

CV mortality:
ASA 1.7%, placebo 1.1%

Composite vascular events:
ASA 10.8%, placebo 10.5%
Nonfatal MI:
0.91 (0.65 to 1.29)

Nonfatal stroke:
0.97 (0.59 to 1.12)

CV mortality:
0.95 (0.77 to 1.7)

Composite vascular events:
1.00 (0.85 to 1.17)
Mahmood, 200357

Patients with CLI after infrainguinal bypass surgery
Retrospective cohort
N: 113
ASA vs. no ASA
Poor
2 yrNonfatal MI:
ASA 1, no ASA 2

Nonfatal stroke:
ASA 2, no ASA 3

CV mortality:
ASA 26, no ASA 9

Composite vascular events:
none reported
Nonfatal MI:
ASA 1.2%, no ASA 5.9%

Nonfatal stroke:
ASA 2.5%, no ASA 8.8%

CV mortality:
ASA 33%, no ASA 26%
a

Number of patients in the study arms of interest.

b

Applies to studies used in the meta-analysis.

Abbreviations: ASA=acetylsalicylic acid (aspirin); CI=confidence interval; CV=cardiovascular; HR=hazard ratio; MI=myocardial infarction; RCT=randomized controlled trial; yr=year/years.

From: Results

Cover of Treatment Strategies for Patients With Peripheral Artery Disease
Treatment Strategies for Patients With Peripheral Artery Disease [Internet].
Comparative Effectiveness Reviews, No. 118.
Jones WS, Schmit KM, Vemulapalli S, et al.

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